public async override Task <UploadResult> InvokeAsync(Stream data, string suggestedFileName, string mimeType, IProgress <TransferProgress> progress, CancellationToken cancellationToken)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
Debug.Assert(UploaderInfo != null);
Debug.Assert(UploaderInfo.Uploader != null);
Debug.Assert(!string.IsNullOrWhiteSpace(suggestedFileName));
Debug.Assert(!string.IsNullOrWhiteSpace(mimeType));
// If the stream has a specific length, check if it exceeds the set maximum file size
var mfs = UploaderInfo.Uploader.MaxFileSize;
if (mfs.HasValue && mfs.Value > 0 && data.CanSeek)
{
var size = data.Length;
if (size > mfs.Value)
{
var memSize = new MemSize(mfs.Value);
throw new UploadException($"File is {memSize} in size, which is larger than the specified limit of {nameof(UploaderInfo.Uploader.MaxFileSize)}.");
}
}
var uplInfo = UploaderInfo.Uploader;
using var progressHandler = new ProgressMessageHandler(new HttpClientHandler());
using var cl = new HttpClient(progressHandler);
progressHandler.HttpSendProgress += (s, e) => progress.Report(TransferProgress.FromHttpProgressEventArgs(e));
// Add the user-agent first, so the user can override it
cl.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent", SuggestedUserAgent);
if (uplInfo.Headers != null)
{
foreach (var(header, value) in uplInfo.Headers)
{
cl.DefaultRequestHeaders.TryAddWithoutValidation(header, value);
}
}
var responseParser = uplInfo.ResponseParser;
using var content = new MultipartFormDataContent();
var postParams = uplInfo.PostParams;
if (postParams is not null)
{
foreach (var(name, value) in postParams)
{
content.Add(new StringContent(value), name);
}
}
var fname = uplInfo.GetEffectiveFileName(suggestedFileName);
Debug.Assert(!string.IsNullOrWhiteSpace(uplInfo.FileFormName));
Debug.Assert(!string.IsNullOrWhiteSpace(fname));
content.Add(new StreamContent(data), uplInfo.FileFormName, fname);
Debug.Assert(!string.IsNullOrWhiteSpace(uplInfo.RequestUrl));
var res = await cl.PostAsync(uplInfo.RequestUrl, content, cancellationToken).ConfigureAwait(false);
if (!res.IsSuccessStatusCode)
{
throw new UploadException($"The servers of {UploaderInfo.Meta.Name} responded with the error {res.StatusCode}: \"{res.ReasonPhrase}\".");
}
var resStr = await res.Content.ReadAsStringAsync().ConfigureAwait(false);
var urlTemplateSpec = responseParser.UrlTemplateSpec;
// As the URL template is optional, we just take the entire response if it is not there
if (urlTemplateSpec == null)
{
return(new UploadResult(this, resStr, DateTime.Now));
}
try
{
var imageUrl = urlTemplateSpec.Evaluate(resStr);
Debug.Assert(!string.IsNullOrWhiteSpace(imageUrl));
return(new UploadResult(this, imageUrl, DateTime.Now));
}
catch (UnableToFillTemplateException e)
{
throw new UploadException(e.Message, e);
}
}
